Mealworms vs. Discoid Roaches for Blue Tongue Skinks: Which Feeder Wins

I've fed blue tongue skinks for years, and the mealworm-versus-roach question comes up constantly because both are everywhere and cheap. The short answer: discoid roaches (Blaberus discoidalis) are the better staple and mealworms are a treat. Here's the actual nutrition behind that call so you can decide for your own animal.

Blue tongues are omnivores — in the wild they eat snails, insects, carrion, greens, and fruit. In captivity that means a mix of vegetables and protein, and the protein portion is where feeder choice matters.

The nutritional head-to-head

These ranges come from feeder-insect nutrition analyses; exact numbers shift with how the insects were raised and gut-loaded.

Protein

Roaches edge out mealworms and deliver more usable protein per feeder because more of the insect is digestible meat rather than shell. For a growing skink that needs muscle and tissue, that efficiency matters.

Fat

This is the biggest gap. Mealworms are fatty — fine for an underweight animal, but feed them as a staple to a sedentary adult skink and you're looking at obesity and fatty liver risk over time. Discoid roaches are leaner and make a better everyday protein.

Calcium and phosphorus — read this carefully

You'll see a lot of sources claim discoid roaches have a "favorable" or "1:1" calcium-to-phosphorus ratio. That's not accurate. Like virtually every feeder insect, both mealworms and discoids are phosphorus-heavy and don't supply the roughly 2:1 calcium-to-phosphorus a reptile's bones need. The fix is the same for both: dust with a calcium supplement (with D3 unless your skink gets UVB) and gut-load the feeders with calcium-rich greens like collard and dandelion. Don't let either feeder's marketing talk you out of supplementing — that's how metabolic bone disease starts.

Digestibility

Mealworms have a stiff chitin shell that's slower to break down and, in quantity, raises impaction risk in juveniles and sensitive animals. Discoids have a softer body and a higher meat-to-shell ratio, so they digest more easily and absorb more fully.

Cost and availability

Mealworms are the convenience champ: cheap, in every pet store, cold-hardy, and shippable year-round. Discoids cost a bit more and are sometimes shipped from specialty breeders, and they're cold-sensitive so winter shipping needs heat packs. The trade-off: a discoid colony breeds readily and pays for itself, while mealworms you just keep buying.

Feeding behavior

Skinks often hit mealworms hard because of the wiggle, but lose interest once a mealworm goes still. Discoids move more steadily and their larger size suits an adult skink's appetite — though a skink new to roaches may need a feeder crushed or pre-killed the first few times to get the idea.

The verdict

Make discoid roaches your insect staple for a blue tongue skink: leaner, more protein, softer, easier on the gut. Keep mealworms as an occasional treat or for putting weight on a thin animal. Rotate in other feeders — silkworms, dubia, the occasional hornworm for hydration — to broaden the nutrient base, and always dust and gut-load. Variety plus supplementation beats any single "perfect" feeder.

If you want to make discoids your staple, All Angles Creatures carries live discoid roaches in sizes from nymph to adult so you can match the feeder to your skink.

For the science on reptile calcium needs and metabolic bone disease, see the Merck Veterinary Manual on metabolic bone disease in reptiles, and the University of Florida IFAS Extension for general feeder-insect husbandry.

Curious how discoids stack up against the other go-to roach? Read discoid vs. dubia, or browse every feeder at the exotic animals hub.